Monolithically integrated mid-IR interband cascade laser and photodetector operating at room temperature

We report on the demonstration of a monolithically integrated mid-IR interband cascade (IC) laser and photodetector operating at room temperature. The base structure for the integrated laser and detector is a six-stage type-I IC laser with GaInAsSb quantum well active regions. The laser/detector pair was defined using focused ion beam milling. The laser section lased in cw mode with an emission wavelength of similar to 3.1 mu m at 20 degrees C and top-illuminated photodetectors fabricated from the same wafer had Johnson-noise-limited detectivity of 1.05 x 10(9) cm Hz(1/2)/W at this wavelength and temperature. Under the same condition, the detectivity for the edge illumination configuration for the monolithically integrated laser/photodetector pairs is projected to be as high as 1.85 x 10(10) cm Hz(1/2)/W, as supported by experimentally observed high photocurrent and open-circuit voltage. These high performance characteristics for monolithically integrated IC devices show great prospects for on-chip integration of mid-IR photonic devices for miniaturized sensors and on-chip optical communication systems. Published by AIP Publishing.